Introduction, life cycle, damage pattern and control measures of Pieris brassicae

1. Pieris brassicae (Cabbage pest)
Kishor Dahal

2. Systematic position
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Pieridae
Genus: Pieris
Species: brassicae

3. Introduction
Pieris brassicae is commonly called cabbage butterfly
or large white butterfly. In the context of Nepal it is
found as subspecies Pieris brassicae nepalensis.

4. Morphology
The cabbage butterfly is yellowish white in color. The
apical angle of forewings black while rest of the wing
is yellowish white. There are two Black spots on each
forewings. The length of the butterfly is 65mm across
the wing expansion. Females are little longer than
male.

5. Distribution
It is cosmopolitan in distribution where cabbage is
cultivated.

6. The main host plant is cabbage but it also feeds on
cauliflower, radish, broccoli etc.
Host plant

7. The larva of Pieris damage the leaves of cabbage. They
feed on the leaves of cabbage and cauliflower and thus
destroy them.
Importance

8. Life cycle
The young larva are about 2 mm in length and light yellow in color. The
body is hairy.
The female lays 50-80 eggs usually in cluster on the undersurface of the
leaves. The eggs are yellow in color, flask shaped and about 1 mm long and
0.5 mm wide. Incubation period varies between 3 days in summer and 18
days in winter.

9. The larval period last for 15 days in summer to 40 days in winter. Full
grown larva is 19 mm in length, bluish green in color with yellowish grey
shades and posses 5 pairs of pseudo legs
It pupates on leaves of cabbage. The pupa is enclosed within a silken
cocoon. The pupal period varies from 7 days in summer to 29 days in
winters. The female copulates just after emergence and begins to lay
eggs.

10. Life cycle

11. Life cycle

12. Initially the caterpillars feed in groups and at this stage
they should be collected and destroyed. The full grown
caterpillars are not much active and can be seen
moving anywhere in the fields, therefore, they can be
picked by hand and killed. If necessary, spraying of
0.05 % carbaryl or 0.03 % dichlorovos or 5 %
malathion is quite satisfactory in checking their
infestation.
Control measures